I think it gets at something vitally important about the (usually) fairly moderate character of American nationalism. It has always seemed to me that liberal critics of American exceptionalism (as President Obama sometimes was) fail to see that what goes by the name of American exceptionalism is actually a moderating influence on American nationalism, because it holds our nationalism up to a standard rather than using nationalism itself as a standard. In other words, our idealistic sense of what America stands for gives us high expectations of ourselves that we sometimes actually take seriously.

Trump’s appeals to nationalism, which certainly seem genuine and which are also in some important respects constructive and valuable, do not benefit from this moderating tendency. Trump champions American nationalism but not American exceptionalism.